Techniques of Water Resources Investigations publication, "Finite-difference model for aquifer simulation in two dimensions with results of numerical experiments,"


               UNITED STATES DEPARTMENT OF THE INTERIOR
                           GEOLOGICAL SURVEY
                        RESTON, VIRGINIA  22092

                                                      GW Branch

                                                August 27, 1976
                                                 Code 4351 5016

GROUND WATER BRANCH TECHNICAL MEMORANDUM NO. 76.12-T

Subject:  PUBLICATIONS - Techniques of Water Resources
                         Investigations publication, "Finite-
                         difference model for aquifer simulation
                         in two dimensions with results of
                         numerical experiments," Book 7, Chapter
                         C1, by P. C. Trescott, G. F. Pinder, and
                         S. P. Larson.

The attached techniques manual by Peter Trescott, George Pinder,
and Steve Larson supersedes the techniques manual published in
1970 entitled, "A digital model for aquifer evaluation," by
George F. Pinder as Chapter C1 of Book 7.  The new Chapter C1
represents a significant improvement in the computation capability
to solve the flow equations and has greater flexibility in the
hydrologic situations that can be simulated.  The model will
simulate ground-water flow in an artesian aquifer, a water-table
aquifer, a combined artesian and water-table aquifer, or an
aquifer that changes from artesian to water-table conditions, or
vice versa.  It may also simulate certain types of cross sectional
flow problems.  The aquifer may be heterogeneous and anisotropic
and have irregular boundaries.  The source term in the flow
equation accommodates multiple pumping periods, recharge, leakage
from confining beds in which the effects of storage are
considered, and evapotranspiration from a water-table aquifer as a
linear function of depth to water.

The model allows the user to select an equation-solving scheme
from among the iterative alternating-direction implicit procedure
(IADIP), line successive overrelaxation (LSOR), and the strongly
implicit procedure (SIP).  Results of numerical experiments are
provided to give some insight as to the numerical scheme that may
be preferable for a given flow problem.



                               (s) Charles A. Appel
                               for Chief, Ground Water Branch
                               Water Resources Division

Attachment

WRD Distribution:  A, B, S, FO, PO